JPS6273046A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a refrigeration system using a compressor, and particularly to a refrigeration system for obtaining an extremely low temperature using a mixed refrigerant of multiple types.

(B) Prior Art Conventionally, freezing equipment used in freezers used in physical and chemical laboratories and the like to preserve biological cells has had a limit of being able to obtain a low temperature of about -80°C. Although cryopreservation of cells is achieved at such low temperatures, as time passes, the nuclei of ice crystals within the frozen cells recombine and the size of the ice crystals expands, causing cell destruction. . This is called recrystallization of ice, but it is known that this recrystallization of ice does not occur in an environment lower than -130° C., which is the recrystallization point. That is, permanent preservation of cells can be achieved at ultra-low temperatures lower than -130°C, and a freezing device capable of achieving such ultra-low temperatures has been expected.

In this type of refrigeration system, especially one using a compressor, the high-temperature gaseous refrigerant discharged from the compressor flows into the condenser and is liquefied by exchanging heat with air or water, and the pressure is adjusted by a pressure reducing device. After that, it flows into an evaporator and is evaporated.

At this time, the cooling effect is achieved by absorbing the heat of vaporization from the surroundings, but in a refrigeration system using a single refrigerant, a normal compressor can achieve a minimum temperature of about -40℃. is the limit.

There is also a so-called dual refrigeration system that uses two independent refrigerant closed circuits, connects them in cascade, and seals a low boiling point refrigerant in the refrigerant closed circuit on the side that achieves the low temperature, thereby achieving a low temperature. However, when using a normal compressor, the temperature is limited to about -80°C.

Further [U.S. Pat. No. 3,768.2, dated October 3, 1973]
As in No. 73, using multiple types of mixed refrigerants with different boiling points,
By evaporating the refrigerant with a higher boiling point and condensing the refrigerant with a lower boiling point one after another, the refrigerant with the lowest boiling point is evaporated in the final stage, resulting in a low temperature achieved by a single compressor.So-called mixed refrigerant refrigeration There are other methods, but those that use a normal compressor have pressure and temperature limits, and -8
A final temperature of about 0°C is the limit.

As a way to solve the shortcomings of these methods at the same time, 19
As in U.S. Patent No. 3,733.845 dated May 22, 1973, two independent closed refrigerant circuits are connected in cascade, and the refrigerant closed circuit on the low temperature side is used as the aforementioned mixed refrigerant refrigeration method to achieve extremely low temperatures. There is.

P→ Problems to be Solved by the Invention According to the configuration as in U.S. Patent No. 3,733,845, it is possible to achieve ultra-low temperatures lower than -130°C using a commonly used compressor (for example, about 1.5 HP). However, in order to achieve an ultra-low temperature lower than -130°C, it is necessary to achieve sufficient heat exchange in the cascade condenser, and the cascade condenser must be enlarged to ensure the heat exchange area. Since the refrigerant closed circuit on the low-temperature side uses a mixed refrigerant refrigeration system, the size of the refrigeration system itself cannot be avoided, but as the cascade condenser becomes larger, there is a problem that the entire system becomes extremely large. The problem can be solved by dividing the cascade capacitor into a plurality of parts, ie the respective cascade capacitors can be made smaller and their arrangement can be chosen in different ways.

How to divide a cascade capacitor into multiple parts?

By dividing the evaporator of the first refrigerant closed circuit into multiple evaporator parts, and further arranging the high pressure side piping of the second refrigerant closed circuit so as to form a heat exchanger with each evaporator part. This is achieved if each evaporator section of the first closed refrigerant circuit is connected in parallel to the refrigerant flow.

When the temperature of any evaporator section increases, the evaporation pressure there increases, making it difficult for refrigerant to flow into the evaporator.

The humidity in the evaporator section increases further. When the evaporator sections are connected in parallel in this way, once the temperature balance is disrupted, it is amplified and the balance is further disrupted, resulting in a problem that the condensing capacity differs depending on the evaporator section. Furthermore, if the high-pressure side piping of the second refrigerant closed circuit is arranged in series with the refrigerant flow in each of the evaporator sections, it will cause a temperature difference between the evaporator sections (i.e., the upstream evaporator ), causing the above-mentioned balance collapse, and an improvement in heat exchange efficiency cannot be expected compared to a case where the evaporator of the first refrigerant closed circuit is not divided.

In order to solve the problem, the present invention provides independent first and second closed refrigerant circuits, and the evaporator of the first closed refrigerant circuit is connected to the refrigerant flow. The second refrigerant closed circuit is filled with a mixture of multiple types of refrigerants with different lung points, and the high-pressure side piping from the compressor to the evaporator is connected to the second refrigerant closed circuit. The refrigeration system is constructed by constructing parallel piping and disposing a tube to constitute a heat exchanger between each of the first refrigerant closed circuits and the evaporator section.

(E) Effect According to the present invention, each part of the so-called cascade capacitor that connects the IF refrigerant closed circuit and the second refrigerant closed circuit can be downsized, increasing the degree of freedom in installation form, and resulting in downsizing of the entire device. can be achieved. In addition, since the evaporator part of the first refrigerant closed circuit is connected in series with the refrigerant flow, destabilization of the condensing capacity due to temperature or pressure is prevented, and the high pressure side piping of the second refrigerant closed circuit is connected in series with the refrigerant flow. The heat exchange efficiency can be improved by arranging the piping in parallel to the refrigerant flow to each evaporator portion of the first refrigerant closed circuit for heat exchange.

(f) Example The invention will now be described in detail with reference to the drawings.

Fig. 1 shows the refrigerant circuit fi+ of the refrigeration system (R1) of the present invention. (4) is an electric compressor that uses a one-phase or three-phase AC power source that constitutes the high-temperature side refrigerant circuit (2). (・1) The discharge side pipe (4D) is the auxiliary condenser (5)
The auxiliary condenser (5) is connected to the cold σ
E storage storage M, 4-prevention pipe (6) that heats the chamber opening edge
and then the electric compressor (4) oil cooler (
7) and then to a condenser (8). (9
1 is a blower for cooling the condenser (8). Condenser (8)
The refrigerant pipe that exits the refrigerant pipe is connected to the oil cooler Qll of the electric compressor a, which constitutes the low-temperature side refrigerant path (b) path (3), returns to the condenser (8), passes through the dryer α2, and then is depressurized. Vessel α
(Accumulator 05 via the first evaporator (14A) and second evaporator (14B) as the evaporator parts constituting the evaporator) and then the suction side pipe of the electric compressor (4) (
4S). The first evaporator (14A) and the second evaporator (14B) are connected in series, and together constitute the evaporator of the high temperature side refrigerant circuit (2).

The high temperature side refrigerant circuit (2) is filled with R501 refrigerant,
The high-temperature gaseous refrigerant discharged from the tjL dynamic compressor (4) is sent to the auxiliary condenser (5), the 4-piece prevention pipe (6), the oil cooler (7+, the condenser (8), and the oil cooler Qll).
After being condensed and liquefied with heat dissipation, the water contained in the dryer az is removed, the pressure is reduced in a pressure reducer Q31, and the mixture flows into the first and second evaporators (14A) (14B) one after another and evaporates. Each evaporator (14A) (14
B) is cooled, the unevaporated liquid refrigerant is separated by the oxidizer α9, and only the refrigerant gas is returned to the electric compressor (4). The capacity of the 1kL dynamic compressor (4) is, for example, 1.
5 I-(P, each evaporator (14A) in operation
The final temperature of 14B) is between -35°C and -40°C.

The discharge side piping (IOD) of the electric compressor 00 constituting the low temperature side refrigerant circuit (3) is connected to the auxiliary condenser C171 and then to the oil separator. Oil return pipe (19 and dryer G20) returns from oil separator u81 to electric compressor 0■
The dryer (1) is connected to a three-way branch pipe. One of the pipes coming out of the three-way pipe Ca11 is wound around the second suction side heat exchanger Qz of the low temperature side refrigerant circuit (3) in a heat exchange manner, and then is inserted into the first evaporator (14A). It is connected to the first condensation pipe (23A) as a side pipe. Three-way tube c! The other pipe coming out from n was similarly wound around the first suction side heat exchanger Ca of the low temperature side refrigerant circuit (3) in a heat exchange manner, and then inserted into the second evaporator (14I3). Second condensing vibe (2311) as high upper piping
connected to. The first evaporator (14A) and the first condensing pipe (23A) and the second evaporator (14B) and the second condensing pipe (231J) are connected to a cascade condenser (251
and (25B). The first and second pseudo-condensation pipes (23A) (23B) are connected by a collecting three-way pipe □□□, and then connected to the first gas-liquid separator 4 via a dryer (281).

The gas phase pipe C3G coming out of the gas-liquid separator 4 passes through the first intermediate heat exchanger c33 and is connected to the second gas-liquid separator. The liquid phase pipe (to) coming out of the gas-liquid separator (c) passes through a dryer (9), and then a pressure reducer ((branch)) to the first intermediate heat exchanger S21 and the second intermediate heat exchanger (4). ' I!J is connected between
After passing through 391, it is connected between the second intermediate heat exchanger G4z and the third intermediate heat exchanger 0a through the pressure reducer (40). intermediate heat exchanger (after passing through the 4D circle, the third intermediate heat exchanger (44)
The pressure reducer (461 is connected to the evaporation pipe (471) as an evaporator, and the evaporation pipe (4η is the third intermediate heat exchanger). The third intermediate heat exchanger (44) is connected to the second intermediate heat exchanger (42) and the first intermediate heat exchanger c3.
2 one after another, and then connected to the accumulator 091, and the accumulator (49) is further connected to the first suction side heat exchanger c! a, and further connected to the suction side piping (IO8) of the electric compressor α0) via the second suction side heat exchanger (2). An expansion tank 6υ that stores refrigerant when the electric compressor aα is stopped is further connected to the suction side pipe (IO3) via a pressure reducer ci2.

The low-temperature side refrigerant circuit (3) is filled with a mixture of four types of refrigerants having different boiling points. That is, R21 (dichloromonofluoromethane), R13B1 (promotrifluoromethane),
R14 (tetrafluoromethane) and R50 (methane)
A mixed refrigerant consisting of is sealed in a pre-mixed state.

The composition of each refrigerant is 4.0% by weight of R50 and 40% by weight of R14.
5% by weight, R13B1 53.4% by weight, R21 2.
It is 1% by weight.

R50 is methane, which causes an explosion when combined with oxygen, but the danger of explosion is eliminated by mixing it with each fluorocarbon refrigerant in the above proportions. Therefore, even if a mixed refrigerant leakage accident occurs, an explosion accident will not occur.

Here, in the embodiment, the evaporator of the high temperature side refrigerant circuit (2) is divided into two evaporator parts, namely, a first and second evaporator (14A) (14, first and second condensing i (23A), (23B)). , two cascade capacitors (25A) (25
Although B) is configured, the present invention is not limited thereto, and there is no problem in dividing it into more cascade capacitors without departing from the spirit of the present invention.

The high temperature and high pressure gaseous mixed refrigerant discharged from the electric compressor (10) is precooled in the auxiliary condenser αn, and then transferred to the oil separator G.
At 81, most of the lubricating oil in the electric compressor 0■ mixed with the refrigerant is returned to the oil return pipe (I9 to the electric compressor (101), and the refrigerant itself passes through the dryer, and then passes through the three-way pipe C! The refrigerant is divided into two parts at υ.The refrigerant divided into two parts by the three-way pipe is separately pre-cooled in the suction side heat exchanger (2z or (2), and then transferred to a cascade condenser (25A) or (2), respectively.
25B) to the first (14A) or second evaporator (
14B) to condense and liquefy part of the refrigerant with a high boiling point in the mixed refrigerant, and then merge in the three-way pipe (5). At this time, the mixed refrigerant is divided into two parts and each is connected to a cascade condenser (25A) or a cascade condenser (25A) or a (25A)
5B), sufficient heat exchange takes place and the condensation effect is well achieved.

The mixed refrigerant coming out of the three-way pipe (5) passes through the dryer and flows into the gas-liquid separator. At this point, R14 and 1 in the mixed refrigerant
150 has an extremely low boiling point, so it is not condensed yet and is in a gas state, and only R21 and R13B1 have been reduced in M, so R14 and R50 are added to the gas phase piping 00), and R21
and R13B1 are separated into liquid phase piping diagrams. The refrigerant mixture that has flowed into the gas phase distribution tank exchanges heat with the first intermediate heat exchanger r, 32 and is condensed, and then passes through the gas-liquid separator. Here, low-temperature refrigerant returning from the evaporation pipe (41) flows into the first intermediate heat exchanger ω, and R13B1, which has further flowed into the liquid phase pipe 041, passes through the dryer (toward) and enters the pressure reducer μs). After being depressurized, it flows into the first intermediate heat exchanger (34) and contributes to cooling by evaporating there, so the temperature of the first intermediate heat exchanger C33 is about -70°C. R14 in the mixed refrigerant that has passed through the gas phase pipe (2)) is condensed and liquefied, and R50 is still in a gas state because it has an even lower boiling point. Therefore, R14 is transferred from the gas-liquid separator C331 to the liquid phase piping diagram.
passes through the drying Masuda, is depressurized at the pressure reducer (4α) and flows into the second intermediate heat exchanger (42) and the third intermediate heat exchanger (42). The return low-temperature refrigerant from the evaporation pipe (471) flows into the second intermediate heat exchanger (471), and the evaporation of 114 further contributes to the cooling trap, so the second intermediate heat exchanger (43 The temperature of is -11
It is about 0″G.The third intermediate heat exchanger (4.
Since the return low-temperature refrigerant from the evaporator pipe (+71) immediately flows into the evaporator pipe, its temperature is extremely low at about -135°C, so the second and third intermediate heat exchangers (47JC+4) and gas phase piping (431
The refrigerant 150 with the lowest boiling point passing through is condensed and liquefied,
After passing through the dryer (45) and being depressurized in the depressurizer (46),
It flows into the evaporation pipe (4η) and evaporates there. At this time, the temperature of the evaporation pipe (4η) has reached -150°C.

This is the final temperature reached by the refrigeration system of the present invention. It becomes possible to
First intermediate heat exchanger f44) (421 Ga ic next k
ic fAt person, m tlJ L, each refrigerant R14,
While merging with R13B1 and R21, the unevaporated refrigerant is separated at the accumulator (edge), and then the suction side heat exchanger C7!4
1 (After being cooled by flowing into 23 one after another, the electric compressor a■
is inhaled.

Here, FL21 that has flowed into the liquid phase pipe C31K in the first gas-liquid separator 4 flows into the first intermediate heat exchanger G, but since it is already at an extremely low temperature, it does not evaporate and remains in a liquid state. Therefore, although they do not contribute equally to cooling, electric compression is performed with residual lubricating oil that could not be separated by oil separator U8 and mixed moisture that could not be completely absorbed by each dryer dissolved in it. It performs the function of returning to the aircraft GO+. When the lubricating oil of the electric compressor (101) circulates in the low-temperature side refrigerant circuit (3), it remains at various parts due to the extremely low temperature.

This may cause clogging. Therefore, almost complete return of the lubricating oil is achieved in 121. By repeating the above steps, the refrigerant circuit (1) is in a steady state and the evaporation pipe (471) is heated to an extremely low temperature of -150°C. , electric compressor +4) Q (11 only requires a capacity of about 1.5 HP, and does not require a particularly large capacity.This is because the heat exchange between the cascade condensers (25A) and (25B) is performed well. This makes a major contribution to the selection of the mixed refrigerant.This achieves noise reduction and low power consumption by the electric compressor.Also, by achieving -150℃, biological materials within the frozen thickness, which will be described later, can be stored in ice. It becomes possible to cool the material to a temperature lower than the recrystallization point, thereby achieving permanent preservation.

Furthermore, the refrigerant in the high temperature side refrigerant circuit (2) is supplied to the first evaporator (14A
) flows to the second evaporator (14B) and is not divided, so even if the temperature balance between the two evaporators (14A) (14B) is disrupted for some reason, an imbalance in the refrigerant flow rate may occur. , therefore, the first condensing pipe (
23A) and the second condensing pipe (23B) are achieved, and a good condensing effect is achieved.

Next, FIG. 2 shows an outline of the control electric circuit of the refrigeration system (R1) of the present invention. (4M) is a motor for driving the electric compressor (4) of the high temperature side refrigerant circuit (2), Alternatively, it is connected between three-phase alternating current power sources (AC).

That is, the motor (4M) is continuously operated while the power (AC) is turned on. (IOM) is a motor for driving the electric compressor α■ of the low temperature side refrigerant circuit (3).

Connect the power supply (AC) (
AC). The contact (60A) is 1r! ,! The coil (60C) of the relay (60) is energized and closed, causing the motor (1ONi) to operate. Q31) is the temperature controller for the freezer storage room, which will be described later, and the power supply (AC) (AC
), it essentially detects the temperature inside the storage chamber, sets an appropriate differential above and below the set temperature, generates a voltage between the output terminals (61A) and (61B) at the upper limit temperature, and generates a voltage between the output terminals (61A and 61B) at the lower limit temperature. Stop occurrence. This set temperature is 11
The temperature is 45°C to -150°C. Output terminal (61A)
(61B) There is a temperature control relay (6z coil (62C)
The contact (63A) of the timer (631) is connected in series.The temperature control relay @ is energized to the coil (62C) and the contact (63A) is connected in series.
Close 62A). The field is the low temperature side refrigerant circuit (3) in Figure 1.
This is a high-pressure switch installed in the electric compressor 0■ discharge side piping (IOD) on the front side of the auxiliary condenser (171).When the high-pressure switch is on, the timer F; ) is connected in series with the electric compressor 00), and when the pressure on the discharge side increases and an excessive load is applied to the compressor σ0), for example, when the pressure rises to 29~, the contact opens,
The contacts are closed when the pressure drops to a sufficiently safe condition, e.g.

The timer hammer closes the contact (63A) 3 to 5 minutes after the high pressure switch contact closes, and the high pressure switch bell opens to open the contact (63A). (60 is a low temperature start thermo stand, which is installed to sense the temperature of the accumulator αS of the high temperature refrigerant circuit (2).
Since evaporated refrigerant and unevaporated refrigerant flow in, the temperature is approximately the same as that of the evaporators (14A) and (14B). , 5°C and close the contacts. Low temperature starting thermostat! 661 constitutes a series circuit with the contacts (62A) of the temperature control relay [F]2 and the timer fold on both sides, and is connected to the power source (AC) (AC). The common terminal of the changeover switch of the timer connection is connected between the timer connection and the low temperature start thermostat (f66), and the terminal of the changeover switch (69A) and the power supply (AC
) A coil (60C) marked with an electromagnetic relay is connected between
Connect the pressure reducer (see Figure 1) between the terminal (69B) and the power supply (AC).
Heaters are installed before and after the decoy for heat exchange. When this cumulative time reaches, for example, 12 hours, the switch is closed to the terminal (69B) for, for example, 15 minutes, and then the terminal (69 people) is closed again.

Next, the operation will be explained. When the refrigeration equipment is installed and the power (AC) is turned on, the motor (4M) starts, the electric compressor (4) operates, and the high temperature side refrigerant circuit (2
) The refrigerant begins to circulate inside. At this time Akeem Lator 05
) is close to room temperature, so it is a cold start thermostat)
66) is in an open state, so regardless of the temperature controller example, the coil (6QC) of the electromagnetic relay 60 is not energized, and therefore the contact (60A) is open, so the motor (IOM) is not started. Therefore, the electric compressor α0) of the low temperature side refrigerant circuit (3) does not operate. Such a cooling operation of only the high temperature side refrigerant circuit (2) continues, and the temperature decreases as liquid refrigerant accumulates in the first and second evaporators (14A) (14B), and accordingly, the accumulator When the temperature of a9 decreases to -34°5℃, the low temperature start thermostat (661) closes the contact.At the moment just before this closing operation, the electric compressor 00) is stopped, so naturally the high pressure switch is closed. Also, since 3 to 5 minutes have passed since the power was turned on, the timer field is also connected to the contact point (63A).
) is closed. Furthermore, since the temperature in the storage room is naturally higher than the set temperature, the temperature regulator 6υ is also generating an output, so the contact (62A) of the temperature control relay (6z) is closed.Therefore, when the low temperature starting thermostat trowel closes, The coil (60C) of the electromagnetic relay (60) is energized and the contact (60
A) is closed, the motor (10M) is started, and the mixed refrigerant is discharged from the electric compressor α■ and begins to be circulated within the circuit (3).

At this time, the temperature of each part of the low-temperature side refrigerant circuit (3) is still high, and since most of the refrigerant inside is in a gaseous state, the pressure inside the circuit is high. Furthermore, since the refrigerant is pushed out from the electric compressor a, the pressure in the discharge side pipe (lOD) increases rapidly. If this is left unattended, the high pressure will damage the components of the electric compressor (101), but when the peak value of this pressure rise reaches the permissible limit of 29, the high pressure switch will sense this and open the contact. (The contact (62A) of the temperature control relay 6z is forcibly opened, the coil (60C) is de-energized, the contact (60A) is opened, and the motor 11 (IOM) is stopped. This prevents pressure rise on the electric compressor (1G discharge side) and prevents damage.

When the electric compressor marked A stops, the pressure in the discharge side piping (IOD) drops to 19 degrees, but due to the presence of a timer to prevent chattering, the contacts do not close for 3 to 5 minutes after the high pressure switch closes. .

Therefore, the motor (IOM) will not start. During this time, the pressure in the low temperature side refrigerant circuit (3) decreases to the first or second evaporator (
14A) (14B) to the first or second condenser (23
Since the refrigerant cooled in step 7 (23B) is circulated to some extent and evaporated, the temperature and pressure have decreased compared to the previous startup. When the delay time set by the timer (timer hammer) has elapsed, the contact (63A) is closed again and the motor (IOM) is started in the same manner as described above, but the discharge side piping (1
When the pressure of 0D) reaches 295, the high pressure 2 innotero ω is opened again and the motor QOI is stopped. By repeatedly starting and stopping such a motor (10M), the refrigerant with a high boiling point evaporates and gradually exerts a cooling effect, so that the temperature gradually decreases from the first intermediate heat exchanger O. As the motor (l OM) starts up, the discharge side piping (l
When the peak value of the pressure increase (OD) no longer reaches 29%, the motor (IOM) enters continuous operation.

As the electric compressor (1α) is operated continuously, the refrigerant with a low boiling point is condensed and gradually begins to exert a cooling effect, and each intermediate heat exchanger C3: D (44) and evaporation pipe (47)
The temperature is gradually lowered to reach the final temperature mentioned above. After that, if the temperature in the storage room is different from the lower limit temperature set by the temperature controller (61), the output terminals (61A) (61B)
Contact because it stops generating output between! (62A) opens,
Furthermore, since the contact (60A) also opens, the motor (10M) stops and the cooling operation stops. After that, the temperature inside the storage chamber gradually rises and when it reaches the upper limit temperature set by the temperature controller Q3B, the contact (62A) closes again, and then the contact (60A)
) is closed, the motor (10M) is started, and cooling operation is started again. By repeating the above steps, the storage chamber is maintained at an average set temperature of, for example, -145°C.

Here, the timer hammer contacts (62A) and the cold start thermostat) (661) are closed, i.e. the motor (1
0M) is in operation, and when this integration reaches 12 hours, the changeover switch side is connected to the terminal (69B).
), so operation of the motor (10M) is prohibited.
Heater qOσυ is energized and generates heat.

Here, R50 which exits 41 to the third intermediate heat exchanger and flows into the pressure reducer (4e) has reached an extremely low temperature of -130°C or less.Therefore, there is an extremely small amount of moisture in this refrigerant (this is If the pressure intrudes during replenishment work), freezing will occur in the pipes.By the way, since pressure reducers are usually constructed of small diameter pipes, this pressure reducer (4
6) When ice grows, clogging occurs and the refrigerant stops flowing. However, in the present invention, since the pressure reducer (40) is periodically heated by the heater σO)συ, the ice crystals are melted and grown. Therefore, such an accident is prevented.The heat generation of this heater σ0)συ is finished in 15 minutes, and the switch (6CJ is closed to the terminal (69A) again and the motor (
IOM) is started, and the cooling operation of the low temperature side refrigerant circuit (3) is started as described above.

Next, FIG. 3 shows a front perspective view of a freezer (75) to which the present invention is applied, and FIG. 4 shows a sectional view of a main part thereof.

Furthermore, Figure 5 shows the refrigerant circuit of the old refrigeration system (II), which is the main body that forms an upper opening to the storage chamber inside, and the upper opening is the rear part of the main body. It can be opened and closed by an insulating door ση which is rotatably supported.A machine room is formed on the side of the main body σ4) to house and install a temperature controller 6υ, an electric compressor (4) αα, etc. In front of it is a self-recording temperature recorder σ9 that senses the temperature inside the storage chamber (76) and records its time course on recording paper.
A well-known alarm box that issues an alarm in case of an abnormally high temperature in the storage room σQ and a knob @D for changing the settings of the temperature controller 6D are provided. Moreover, g3a is a slit for ventilation.

FIG. 4 shows a side sectional view of the main body σ4) portion.

(f) is a steel plate outer box with an upward opening, - is an aluminum inner box with an upward opening, and the inner box (goods) is assembled inside the outer box □□□, and both boxes g! A box-shaped external insulation material (851 and an internal insulation material □
A double heat insulating layer consisting of □□ is formed, and the opening edges of both boxes are connected by a breaker t8η. Inner box (84
) An evaporation pipe (4η) is arranged on the outer surface of the pipe for thermal conduction.
It is buried in the inner heat insulating material (a), and a garden prevention bayder (6) is disposed on the inner surface of the opening edge of the outer box σe for thermal conduction. The inner insulation material is placed inside the outer insulation material (H) and is completely separated, so even if the inner insulation material (G) contracts due to the cooling action of the evaporation pipe (four forces), the outer insulation material It does not have the same effect on the timber field, so cracks in the insulation material do not occur, and sufficient insulation performance is maintained.An opening is formed on the back of the outer box, and an opening is formed on the back of the outer box. Insulation material□□□
A corresponding notch field is formed in the notch C9, and a cascade capacitor (25A) molded with a heat insulating material (90) as described later is inserted through the opening (c) in this notch C9.
(25B) etc. are stored and arranged and covered with a cover plate 0υ. (Inner lid made of 9-piece styrofoam, (G) is an insulated door σ
η is a gasket on the inner circumferential surface, and is a caster for transportation.

Next, Figure 5 shows the specific configuration of the refrigerant circuit (1) of the refrigeration system (R1), in which the same symbols as in Figure 1 are the same.Auxiliary condensation of the low temperature side refrigerant circuit (3) The container a1 is arranged on the windward side of the condenser (8) of the high temperature side refrigerant circuit (2) with respect to the air suction type blower (9), so that it is cooled at the same time.The first and second evaporators (14A) (14B)
has the shape of a hollow tank, and inside this are first and second condensing pipes (2) spirally wound from above.
3A) (23B) are inserted respectively. (66
A) is a cylindrical body for fixing the accumulator (low-temperature start thermostat 6 fixed to one by welding). (a) shows the intermediate heat exchanger section which is made up of intermediate heat exchangers C321 (43 (44), etc., which will be described later) and is molded into a box shape using heat insulating material. It is fixed to the outside of the box (goods) in a serpentine shape with aluminum tape or adhesive, but in order to minimize the temperature distribution in each part of the storage room συ, the order in which the refrigerant flows is adjusted to the inner box ( It is arranged so that it goes around the top of the building, goes around the bottom, and finally goes around the bottom.

Figure 6 shows the structure of the intermediate heat exchanger section (a). The part surrounded by the dotted line is the first, second and third intermediate heat exchanger Ct3 (4
2nd gas-liquid separator can, dryer G9 (4 pieces, pressure reducer (
4G and accumulator (intermediate heat exchanger section (a) containing a fence.Each intermediate heat exchanger C33 (4Z (44)
In this example, relatively large-diameter outer piping (G) and (B) are wound spirally in multiple stages to form a flat structure, which are then superposed on each other, and each gas phase piping example (43 is It is composed of a spiral double pipe structure that passes through as an inner pipe, and the part (B) in the figure is the first intermediate heat exchanger (c3), and the part (B) is the second intermediate heat exchanger (4δ, In addition, (0 part becomes the third intermediate heat exchanger (4 (a) 49 is housed to reduce dead space and reduce size.

Next, the configuration will be explained. (101) is the dryer (to) and the first
This is the piping that connects the gas-liquid separator ■. The gas phase pipe ■ coming out upward from the first gas-liquid separator ■ has a sealed inlet (IN,)
It enters the outer side of the piping, passes through the interior in a spiral pattern, exits from the outlet (OUT), and enters the second gas-liquid separator (
to go into. The gaseous refrigerant flowing down in the gas phase piping diagram is condensed by the low temperature refrigerant rising through the gap between the gas phase piping (2) and the outer piping (G) during this passage. The gas phase pipe 03 coming out from between the second gas-liquid separators enters the outer pipe @circle from the inlet (IN2). The liquid refrigerant separated in the first gas-liquid separator C29) is depressurized by the pressure reducer (G), and then connected to the outlet (OUT,) of the outer pipe ((G)) and the inlet (IN,) of (991). The refrigerant flows into the connecting connecting pipe (102), evaporates in the outer pipe (G), and contributes to the condensation of the gaseous refrigerant in the gas phase piping diagram together with the refrigerant returning from the evaporation pipe (471).Outer piping !9 gas phase piping (43 is the outlet (OUT))
It exits from the inlet (IN,), enters the outer pipe (2) again through the inlet (IN, ), circles around in a spiral pattern, and exits through the outlet (OUT, ). The outer piping of each outlet and inlet section is sealed.

The liquid refrigerant separated by the second gas-liquid separator ω is transferred to a pressure reducer (41
After the pressure is reduced by
) and the communication pipe (103) connecting the inlet (IN, ) of (9).
) The refrigerant flows into the outer pipe (99) and evaporates into the gas phase pipe (0) along with the refrigerant returning from the evaporation pipe (41).
Contributes to the condensation of the gaseous refrigerant within 3. The refrigerant (R50) flowing down through the gas phase pipe (43) is further condensed and almost liquefied as it passes through the outside pipe (2), and reaches the pressure reducer (46) through four dryers. (105) is the evaporation pipe (4
7] is connected to the outlet (OUT, ) of the outer pipe (9), and communicates with the gas phase pipe 31 outside the space. (106) is the inlet of the outer pipe (
This is a pipe that communicates the outer space of the gas phase pipe (7) with the accumulator (4! The refrigerant flows into the space between the phase pipe IA3 and rises there, condenses the refrigerant flowing down in the gas phase pipe (431), and joins with the refrigerant from the pressure reducer (401) through the communication pipe (103). The refrigerant flows into the space between the outer pipe (99) and the gas phase pipe (431), rises there, condenses the refrigerant in the gas phase pipe (43), and then flows from the pressure reducer (1) through the communication pipe (102). It joins with the refrigerant, flows into the space between the outer pipe ω~ and the gas phase pipe example, rises there, condenses the refrigerant in the gas phase pipe □□□, passes through the pipe (106), and flows into the accumulator ( The refrigerant flows into the suction side heat exchanger Q4J through the pipe (108).As shown above, the flow of the refrigerant flowing down in the gas phase piping diagram (43) and the gas phase distribution from the evaporation pipe (4η)
Alternatively, the flows of refrigerant rising between 431 and the outer pipes 0(g) and 0g(g) are mutually opposing flows.

Next, Fig. 7 shows a rear perspective view of the freezer σ■.
(To) The installation procedure will be explained. Openings (110) are formed on the back surface of the outer box in parallel with the openings, and correspondingly notches (111) are also formed in the outer heat insulating material. A cascade capacitor (25
A) Mold the suction side heat exchanger (22+02 side Akie emulator a9 and dryer slurry) together with (25B).The molding method for the heat insulators ω and It is installed in a shaped foam mold, and the bag is filled with foam and molded with urethane insulation material.The pressure reducer 061 and piping (105) are extended from the insulation material edge, and the notch (111) is inserted into the bag. Derivation part at the back (112) (112)
It is connected to the evaporation pipe (47) led out by welding. The piping of the pressure reducer (131, etc.) extending from the insulation material is welded to the piping led out from the wall on the machine room σa side of the notch. ) is located on the outside of the insulation material, and the insulation material [-] is also connected to the notch (89) and (111) and installed in the notch (89) (111). After filling the gap with glass wool, etc., insert the cover plate (91)
) to complete the assembly by cutting the notches S81 and (111). In addition, electric compressor (41QOl, condenser (8)
, the blowing loss (9), the expansion tank 6v, etc. are installed in advance in the machine room σ ink pad, thereby completing the freezer σ9.

The self-recording temperature recorder σ9 records the temperature inside the storage chamber σe, and is one of the important components in this type of freezer. By the way, blood recorders are generally made using the well-known Archimedean spiral-shaped Bourdon tube (120 mm) as shown in Figure 8.
) and a recording paper (not shown) that is automatically moved as time passes.

In FIG. 8, (121) is a temperature sensing part arranged to sense the temperature inside the storage chamber σ6), and the Bourdon tube (12
0) and the temperature sensing section (121) are connected to each other through a thin tube (122). A drive shaft (123) is erected and fixed, for example, at the center (0) of the spiral of the Bourdon tube (120), and a recording pointer (124) is attached to the tip of the drive shaft (123). The Bourdon tube (120) has a hollow interior, and a temperature-sensitive substance such as ethyl alcohol or n-propyl alcohol is sealed therein in liquid form. The Bourdon tube (120) is deformed by changes in internal pressure caused by changes in temperature around the temperature sensing part (121), and rotates the drive shaft (123) in the axial direction. It is known that the change in pressure inside the tube (120) is proportional to the change in pressure, and the temperature inside the storage chamber Qe is thereby converted to the position of the pointer (124) and recorded.

By the way, general temperature-sensitive substances such as ethyl alcohol and normal propyl alcohol are used at temperatures around -80°C, and they freeze at extremely low temperatures such as -150°C, which is the subject of the present invention, and cannot be used with temperature recorders. It cannot be used as such.

Therefore, as a result of intensive research, in the present invention, 2-
By enclosing methylpentane (inhexane), it was possible to record temperatures at extremely low temperatures such as -150°C. Figure 9 shows 2-methylpentane in a Bourdon tube (1
20) shows the relationship between the ambient temperature (T') of the temperature sensing part (121) and the pressure port in the Bourdon tube (120) when it is sealed inside. As is clear from the figure, the pressure (Pa bar from 150℃ to +
50'Ctf) mWu Surrounding temperature (approximately proportional to the sword. Here, the rotation angle of the pointer (124) is the pressure (P) as described above.
Since it is proportional to l, it is also approximately proportional to temperature ■, and therefore -
The temperature in the storage chamber σ■ can be recorded in the range from 150°C to +50°C.

(G) Effects of the Invention According to the present invention, extremely low temperatures can be achieved with a normal electric compressor without using a high-output electric compressor. At this time, the so-called cascade condenser, which connects the evaporator of the first refrigerant closed circuit and the high-pressure side piping of the second refrigerant closed circuit in a heat exchange manner, can be divided into multiple parts, increasing the degree of freedom in installation configuration and miniaturization is achieved. In addition, each evaporator section of the first refrigerant closed circuit is connected in series with the refrigerant flow, and the high-pressure side piping of the second refrigerant closed circuit has multiple parallel piping, so the temperature balance of each evaporator section can be maintained. There is no imbalance in the refrigerant flow rate due to collapse, each evaporator section exhibits stable condensing ability, and the mixed refrigerant flowing through the high-pressure side pipes also undergoes good heat exchange, resulting in stable ultra-low temperature. It is possible to achieve this.

[Brief explanation of drawings]

Each figure shows an example of an accident caused by non-invention. Figure 1 is a refrigerant circuit diagram of a refrigeration system, Figure 2 is a control electric circuit diagram, and Figure 3 is a diagram of a control electric circuit.
The figure is a perspective view of the freezer, Figure 4 is a side sectional view of the freezer body,
Fig. 5 is a diagram showing the specific configuration of the refrigerant circuit of the refrigeration system, Fig. 6 is a perspective view of the intermediate heat exchanger section, Fig. 7 is a rear perspective view of the freezer, and Fig. 8 is the configuration of the self-recording temperature recorder. FIG. 9 is a perspective view of the Bourdon tube filled with 2-methylpentane, and is a diagram showing the relationship between the internal pressure and the temperature of the temperature sensitive part of the Bourdon tube. (R1...refrigeration device, (2)...high temperature side refrigerant circuit, (3)...low temperature side refrigerant circuit, +41QO)・
...Electric compressor, (14A) 2nd condensing ticket, C33
(43 (44)... Intermediate heat exchanger. △ Agent Patent attorney: Yasuo Sano Figure 7 Figure 8 T (5ゑ1mi"C)

Claims (1)

[Claims] 1. The evaporator that constitutes the first refrigerant closed circuit is composed of independent first and second refrigerant closed circuits that each condense and then evaporate the refrigerant discharged from the compressor to exert a cooling effect. and a plurality of evaporator parts connected in series with respect to the refrigerant flow, the second refrigerant closed circuit is filled with a mixture of refrigerants of multiple types with different boiling points, and high pressure is supplied from the compressor to the evaporator. A refrigeration system in which the side piping is composed of a plurality of parallel pipings, each of which is arranged so as to constitute a heat exchanger between the side piping and the evaporator portion of the first refrigerating circuit.